Adopting feature of buried electrically conductive layer in dielectrics for electrical anti-fuse application

Abstract

An anti-fuse structure that included a buried electrically conductive, e.g., metallic layer as an anti-fuse material as well as a method of forming such an anti-fuse structure are provided. According to the present invention, the inventive anti-fuse structure comprises regions of leaky dielectric between interconnects. The resistance between these original interconnects starts decreasing when two adjacent interconnects are biased and causes a time-dependent dielectric breakdown, TDDB, phenomenon to occur. Decreasing of the resistance between adjacent interconnects can also be expedited via increasing the local temperature.

1. A semiconductor structure comprising:
 an insulator including at least a pair of adjacent interconnects, each interconnect of said pair includes a diffusion barrier material, an electrically conductive interconnect material located on an upper surface of the diffusion barrier material, and a buried electrically conductive layer embedded in a surface of said insulator and in contact with a bottom surface of said diffusion barrier material, wherein each of said buried electrically conductive layers is located on at least one sidewall of said diffusion barrier material of each respective interconnect, each of said buried electrically conductive layers has an upper surface that is coplanar with an upper surface of said electrically conductive material, and each of said buried electrically conductive layers is separated by a dielectric region which permits current flow when a bias is applied between said pair of adjacent interconnects and wherein at least one of said buried electrically conductive layers is located only partially beneath, and on one side of, said diffusion barrier material that contains one of said interconnects. 
 
     
     
       2. The semiconductor structure of  claim 1  wherein said insulator is an organic or inorganic dielectric material. 
     
     
       3. The semiconductor structure of  claim 2  wherein said insulator has a dielectric constant of about 4.0 or less. 
     
     
       4. The semiconductor structure of  claim 1  wherein said insulator comprises one of SiO 2 , an aromatic thermosetting polyarylene ether, a carbon doped oxide comprising atoms of Si, C, O and H, a silsesquioxane, tetraethylorthosilicate (TEOS), or an organosilane. 
     
     
       5. The semiconductor structure of  claim 1  wherein said diffusion barrier material comprises one of Ta, TaN, Ti, TiN, TiSiN, W, WN or Ru. 
     
     
       6. The semiconductor structure of  claim 1  wherein said electrically conductive interconnect material comprises Cu, Al, W or Al(Cu). 
     
     
       7. The semiconductor structure of  claim 1  wherein each of said buried conductive layers comprises Ta, TaN, W, Cu, Al, Pt, Pd, Ru, Rh, Au, or Ag. 
     
     
       8. The semiconductor structure of  claim 1  further comprising a dielectric capping layer atop a surface of said insulator including said pair of adjacent interconnects. 
     
     
       9. The semiconductor structure of  claim 1  further comprising a conductive filled via in said insulator which is in contact with an underlying interconnect embedded in an underlying insulator. 
     
     
       10. The semiconductor structure of  claim 9  wherein said underlying insulator is separated in part from said insulator by a dielectric film, said dielectric film having an opening in which said conductive filled via is in contact with said underlying interconnect. 
     
     
       11. A semiconductor structure comprising:
 a first insulator including at least one embedded first interconnect region; and 
 a second insulator overlying said first insulator, said second insulator comprising at least a pair of adjacent second interconnect regions, each interconnect region of said pair includes a diffusion barrier material, an electrically conductive interconnect material located on an upper surface of the diffusion barrier material, and a buried electrically conductive layer embedded in a surface of said second insulator and in contact with a bottom surface of said diffusion barrier material, wherein each of said buried electrically conductive layer is located on at least one sidewall of said diffusion barrier material of each respective second interconnect region, each of said buried electrically conductive layers has an upper surface that is coplanar with an upper surface of said electrically conductive material, and each of said buried electrically conductive layers is separated by a dielectric region which permits current flow when a bias is applied between said pair of adjacent interconnect regions and wherein at least one of said buried electrically conductive layers is located only partially beneath, and on one side of, said diffusion barrier material that contains one of said interconnects. 
 
     
     
       12. The semiconductor structure of  claim 11  wherein said first and second insulators are the same or different dielectric material selected from organic and inorganic dielectric materials. 
     
     
       13. The semiconductor structure of  claim 12  wherein said first and second insulators have a dielectric constant of about 4.0 or less. 
     
     
       14. The semiconductor structure of  claim 11  wherein said first and second insulators comprise one of SiO 2 , an aromatic thermosetting polyarylene ether, a carbon doped oxide comprising atoms of Si, C, O and H, a silsesquioxane, tetraethylorthosilicate (TEOS), or an organosilane. 
     
     
       15. The semiconductor structure of  claim 11  wherein said first interconnect region includes an optional diffusion barrier material and an electrically conductive interconnect material. 
     
     
       16. The semiconductor structure of  claim 11  wherein said diffusion barrier material comprises one of Ta, TaN, Ti, TiN, TiSiN, W, WN or Ru. 
     
     
       17. The semiconductor structure of  claim 11  wherein said electrically conductive interconnect material comprises Cu, Al, W or Al(Cu). 
     
     
       18. The semiconductor structure of  claim 11  wherein each of said buried conductive layers comprises Ta, TaN, W, Cu, Al, Pt, Pd, Ru, Rh, Au or Ag. 
     
     
       19. The semiconductor structure of  claim 11  further comprising a dielectric capping layer atop a surface of said second insulator including said pair of adjacent interconnect regions. 
     
     
       20. The semiconductor structure of  claim 11  further comprising a conductive filled via in said second insulator which is in contact with said first interconnect region of said first insulator. 
     
     
       21. The semiconductor structure of  claim 20  wherein said first insulator is separated in part from said second insulator by a dielectric film, said dielectric film having an opening in which said conductive filled via is in contact with said first interconnect region. 
     
     
       22. A semiconductor structure comprising:
 an insulator including at least a pair of adjacent interconnects, each interconnect of said pair includes a diffusion barrier material, an electrically conductive interconnect material located on an upper surface of the diffusion barrier material, and a buried electrically conductive layer embedded in a surface of said insulator, wherein each of said buried electrically conductive layers is located on at least one sidewall of said diffusion barrier material of each respective interconnect, each of said buried electrically conductive layers has an upper surface that is coplanar with an upper surface of said electrically conductive material, and each of said buried electrically conductive layers is separated by a dielectric region which permits current flow when a bias is applied between said pair of adjacent interconnects and wherein at least one of said buried electrically conductive layers is located only on one side of said diffusion barrier material that contains one of said interconnects.